Department of Plastic and Reconstructive Surgery, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China.
Cartilage. 2024 Sep;15(3):293-302. doi: 10.1177/19476035231183254. Epub 2023 Jul 4.
The cartilage regeneration field has not yet overcome the issue of effective "shaping": growing regenerated cartilage in the desired shape, and maintaining that shape, is problematic. This study reports on a new method of cartilage regeneration in which the cartilage is shaped in three dimensions. Since cartilage is composed only of cartilage cells and an abundant extracellular matrix with no blood circulation, once it is damaged, the lack of nutrient supply means that it is difficult to repair. Scaffold-free cell sheet technology plays an important role in cartilage regeneration, avoiding inflammation and immune response caused by scaffold materials. However, cartilage regenerated from the cell sheet needs to be sculpted and shaped before it can be used for cartilage defect transplantation.
In this study, we used a new ultra-strong magnetic-responsive Fe3O4 nanoparticle (MNP) to shape the cartilage . Super-magnetic Fe3O4 microspheres are manufactured by co-assembling negatively charged Cetyltrimethylammonium bromide (CTAB) and positively charged Fe3+ under solvothermal conditions.
The Fe3O4 MNPs are swallowed by chondrocytes, and the MNP-labeled chondrocytes are acted upon by the magnetic field. The predetermined magnetic force makes the tissues coalesce to form a multilayer cell sheet with a predetermined shape. The shaped cartilage tissue is regenerated in the transplanted body, and the nano magnetic control particles do not affect cell viability. The nanoparticles in this study improve the efficiency of cell interaction through super-magnetic modification, and to a certain extent change the way the cells absorb magnetic iron nanoparticles. This phenomenon allows a more orderly and compact alignment of the cartilage cell extracellular matrix, promotes ECM precipitation and cartilage tissue maturation, and improves the efficiency of cartilage regeneration.
The magnetic bionic structure, which contains specific magnetic particle-labeled cells, is deposited layer by layer to generate a three-dimensional structure with repair function, and further induce the production of cartilage. This study describes a new method for the regeneration of tissue engineered cartilage which has broad application prospects in regenerative medicine.
软骨再生领域尚未克服有效“塑形”的问题：将再生软骨生长为所需的形状并保持该形状是有问题的。本研究报告了一种新的软骨再生方法，其中软骨在三维空间中成型。由于软骨仅由软骨细胞和富含细胞外基质组成，没有血液循环，一旦受损，缺乏营养供应就意味着难以修复。无支架细胞片技术在软骨再生中起着重要作用，可以避免支架材料引起的炎症和免疫反应。然而，从细胞片再生的软骨需要经过雕刻和成型，然后才能用于软骨缺陷移植。
在这项研究中，我们使用了一种新的超强磁性响应 Fe3O4 纳米颗粒（MNP）来塑造软骨。超顺磁 Fe3O4 微球是通过在溶剂热条件下共组装带负电荷的十六烷基三甲基溴化铵（CTAB）和带正电荷的 Fe3+ 制造的。
Fe3O4 MNPs 被软骨细胞吞噬，并且 MNP 标记的软骨细胞受到磁场的作用。预定的磁力使组织凝聚形成具有预定形状的多层细胞片。在移植体中再生成型的软骨组织，纳米磁控颗粒不影响细胞活力。本研究中的纳米颗粒通过超磁改性提高了细胞相互作用的效率，并在一定程度上改变了细胞吸收磁性铁纳米颗粒的方式。这种现象允许软骨细胞外基质更有序和更紧密地排列，促进 ECM 沉淀和软骨组织成熟，并提高软骨再生的效率。
含有特定磁性粒子标记细胞的磁性仿生结构逐层沉积，产生具有修复功能的三维结构，并进一步诱导软骨的产生。本研究描述了一种组织工程软骨再生的新方法，在再生医学中具有广阔的应用前景。
